[doo, dyoo] 
| a 3000-mi. (4800–km)–long network of radar stations north of the Arctic Circle, maintained by the U.S. and Canada for providing advance warning of the approach of hostile planes, missiles, etc. |
| DEW line (dōō, dyōō) n. A line of radar stations near the 70th parallel across the North American continent, maintained by the United States and Canada and intended to give advance warning of approaching enemy aircraft and missiles. [D(istant) E(arly) W(arning).] |